Purpose: Polymorphism in miR-146a (rs2910164) has been reported to be associated with gastric cancer risk in the Chinese population. We aimed at evaluating the relationship between rs2910164 and the clinical characteristics and outcomes in stage IB-III gastric cancer patients treated with adjuvant chemotherapy after surgery.
Materials and methods: Ninety-eight patients with stage IB-III gastric cancer treated with surgical resection followed by adjuvant chemotherapy of oxaliplatin and fluoropyrimidines were included in the analysis. Genomic DNA was extracted from peripheral blood sample of all patients. Polymerase chain reaction-based restriction fragment length polymorphism assay was used to determine the genotypes.
Results: The 2-year disease-free survival rate was 63%, and the 3-year overall survival (OS) rate was 73.4%. In dominant model, we found that rs2910164 GC + CC (G: guanine, C: cytosine) genotype carriers were less likely to develop lymph node metastasis (P=0.059). The 3-year OS was significantly different for patients with or without lymph node metastasis (89.3% vs 63.7%, P=0.015) and for patients with stage I-III disease (100.0%, 88.6%, and 56.9%; P=0.018). The 3-year OS for GC + CC carriers was significantly higher than for GG carriers (75.1% vs 66.7%, P=0.041). After the multivariant Cox regression analysis, histological grade (P=0.033, relative risk: 5.116, 95% confidence interval: 1.145-22.865) and lymph node status (P=0.031, relative risk: 6.648, 95% confidence interval: 1.191-37.118) were found to be independent prognostic factors for these patients.
Conclusion: rs2910164 could be associated with the lymph node metastasis and prognosis of Chinese gastric cancer patients treated with oxaliplatin and fluoropyrimidines after surgical resection.
Keywords: clinical characteristics; gastric cancer; miR-146a; polymorphism; prognosis.